[libc] Fix start up crash on 32 bit systems (#66210)

This patch changes the default types of argc/argv so it's no longer a
uint64_t in all systems, instead, it's now a uintptr_t, which fixes
crashes in 32-bit systems that expect 32-bit types. This patch also adds
two uintptr_t types (EnvironType and AuxEntryType) for the same reason.

The patch also adds a PgrHdrTableType type behind an ifdef that's
Elf64_Phdr in 64-bit systems and Elf32_Phdr in 32-bit systems.